We propose to investigate the organization of directed spatial attention from the vantage point of a distributed neurocognitive network. The behavioral mechanisms and anatomical correlates of disturbances of overt and covert processes associated with spatial attention will be examined. Specifically designed paradigms will be used to dissect the complex phenomenon of directed attention into exploratory-motor, representational- sensory and motivational components. These experimental paradigms will be given to patients with focal strokes and their controls to yield information about perceptual representation, detection efficiency, exploratory scanpaths and visual dwell times in the right and left hemispaces. Magnetic resonance imaging with 3-dimensional surface reconstruction of the lesion site will be used to precisely delineate the location of structural brain damage. The behavioral components of directed attention will be analyzed with respect to the frontal, parietal, cingulate and subcortical sectors of the postulated neurocognitive network. We expect that the behavioral components will be mapped onto the anatomical sectors of this network in a pattern consistent with regionally specialized distributed processing. These multidimensional studies provide an extension of our previous work on the neurobiology of directed attention and may yield guidelines for the management and rehabilitation of patients suffering from hemispatial neglect.